芒果采后病害拮抗菌的筛选、鉴定及其生防效果研究

Antagonists Selection and Control Effect on Postharvest Diseases of Mango Fruit

采用平板对峙法从芒果叶片与果实分离筛选芒果采后主要病害病原菌(胶孢炭疽病菌Colletotrichum gloeosporioides Penz.,芒果蒂腐病菌Botryodiplodia theobromae Pat.)的拮抗菌,对抑菌效果好的拮抗菌进行采后病害防治试验,并采用形态及培养特征观察、生理生化测定结合16S DNA序列分析进行鉴定。发现菌株A1稀释10倍的LB菌液对芒果采后炭疽病防效为80.05%、对蒂腐病的防效为74.18%,平均防效达到77.12%,防效明显。菌株C13对芒果采后炭疽病和蒂腐病防效次之,防效分别为71.73%和54.24%,平均防效达到62.99%。经鉴定A1为荧光假单胞菌Pseudomonas fluorescens Migula,C13为枯草芽孢杆菌Bacillus subtilis strain。

Leaves and fruits of mango plant were chosen as initial inoculums to isolate antagonists on the main pathogenic fungi Colletotrichum gloeosporioides Penz. and Botryodiplodia theobromae Pat. of mange fruit. Biocontrol effects were evaluated by the method of confronting cul- tures. The high antagonistic activity stains were selected to control postharvest diseases and to determine its classification status by morpholo- gy and culture feature observation, and physiological and biochemical characteristics determination and 16S rDNA sequences assay. The re- sults showed that strain A1 had a high control effect,followed by strain C13. The disease control effect of 10 times dilution oral LB medium on anthracnose and on stem-end rot was 80.05 % and 74.14 % respectively, and average inhibitory rate reached 77.12 % against the 2 pathogens. The disease control effect of strain C13 on anthracnose and on stem-end rot was 71.73 % and 54.24 % respectively, and average inhibitory rate was 77.12 %. After observation on the morphological culture, biochemical property analysis and molecular biology appraisal as well as 16S rDNA sequence, A1 and C13 were identified as Pseudomonas fluorescens Migula and Bacillus subtills strain.